High temperature insulating foams are useful primarily for pipe insulation. Most chemical processing facilities, industrial and residential buildings use some form of foam insulation. In refineries and chemical processing plants, superheated steam is frequently used which is generally above 400.degree. F.
In the past, fiberglass insulation and calcium silicate insulation have served as the primary insulating materials in commercial and residential applications. Unfortunately, these insulating materials degrade over long term exposure to high temperatures. Additionally, these materials are susceptible to water or moisture, which reduces the insulating value substantially.
With respect to isocyanate foams having an initial K factor of about 0.14 to 0.15, fluorocarbon gas tends to migrate out of the insulating cells, causing the conductivity to increase and corresponding resistance to heat transfer to decrease.